Research in comparative visual perception is typically conducted by presenting 2D depictions of 3D objects to assess components of object recognition. The aims of this project are to determine whether nonhuman primates are capable of equating their perceptions of 3D objects and their 2D depictions, and if so, whether they use the global form of the object (overall configuration) or its local details (individual object elements). Subjects will be presented with a 2D depiction of an object with no identifying local features that portrays information about that object. Specifically, subjects will view an image of a 6-doored cabinet on a 2D touch screen monitor. Subjects will search this "virtual cabinet" by touching the images of the doors on the screen to reveal the contents of each compartment. An image of a food reward will be "concealed" behind one of the doors on each trial. Once the subject "reveals" the food from behind this door in the 2D "virtual cabinet" the 3D cabinet will be presented and the subject's actions (i.e. doors opened) will be recorded. If animals are able to complete the cross dimensional task (use the 2D information to find the food in 3D) at levels greater than chance, this will be evidence that they are capable of equating their perceptions of the 2D depiction and the 3D object by utilizing the object's global form. If performance is below chance levels, previous success with cross-dimensional tasks may have resulted from the use of an associative rule such as matching local features from the object to the image or vice versa. [unreadable] [unreadable]